Platen-carriage mechanism for typewriters



0. A. HOKANSON. PLATEN CARRIAGE MECHANISM FOR TYFEWR ITERS.

APPLICATION FILED JUNE I2, 1922?.

.Patented Aug. 29, 1922.

2 SHEETSSHEET I.

0. A. HOKANSON.

- PLATEN CARRIAGE MECHANISM FOR TYPEWRITERS.

. APPLICATION FILED JUNE 2. 1920 IAQZQYU.

Patented Aug. 29,

2 SHEET SS HEET 2.

UNITED STATES PATENT omen.

OTTO A. HOKANSON, OF WOODSTOCK, ILLINOIS, ASSIGNOR TO WOODSTOCK TYPE-WRITER. COMPANY, OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

fi 4227g470:

Application filed June 12,

To all whom it may concern:

Be it known that I, O'r'ro A. HOKANSON, a citizen of the United States,residing at Woodstock,.in the county ofMcHenry and State of Illinois,have invented certain new and useful Improvements in Platen-CarriageMechanism for Typewriters, of wh1ch the following is a specification. I

This invention relates to platen carriage mechanism and especiall to ananti-creeping device for the carriage bearing balls, and has for itsobject the provision of a mechanism of the character named which shallbe of improved construction and operation.

The invention is exemplified in the combination and arrangements ofparts shown in the accompanying drawings and described in the followingspecificatmn, and 1t 1s more particularly pointed out in the appendedclaims.

In the drawings,

Fig. 1 is a top plan view of an anti-creeping ball retainer frameforming a part of the resent invention;

Fig. 2 is an elevation of the frame shown in Fig. 1; I

Fig. 3 is a transverse sectional view of a platen carriage having thepresent invention applied thereto; and

Fig. 4 is a vertical section substant1ally on line 4-4 of Fig. 3.

In the form of platen carriage illustrated in Figs. 3 and 4, the numeral10 designates the bed plate of the latch carriage provided with V-ways11 at t e front and rear edges thereof. The platen carriage comprises amovable plate 12 having V-ways 13 arranged to cooperate with the ways 11and between the ways 11 and 13 hearing balls 14 are 1nterposed. Thecarriage plate 12 may be made in two sections adjustably connectedtogether 0 cap screws 15 which permits of easy assem ling and alsoprovides for an adjustment of the bearings on the balls 14 A ballretainer frame 16, shown in detail in Figs. 1 and 2, is provided forholding the balls 14 in proper position in the ways 11 and 13 and isarranged to travelbetween the bed plate 10 and the carria e plate 12.When the carriage 12 is move along the bed 10 it is apparent that thelinear movement of the balls 14 will normally be half as great as thatof the carriage but in practice there is a tendency for the balls tocreep Specification of Letters Patent.

Patented Aug. 29, 1922.

1920. Serial No. 388,420.

or work toward one end or the other of the ways 11 during continuedmovement of the carriage back and forth upon its ways. In order toprevent a creeping movement of th1s kind, the frame 16 is provided witha projection 17 on which a toothed wheel 18 is journaled in position toengage a rack 19 secured to the carriage bed plate 10, as shown in Figs.1 and 4. A similar rack 20 is secured to the platen carriage plate 12 sothat when the carriage is moved back and forth upon its bed, the toothedwheel 18 will travel between the two relatively movable parts at a speedequal to half. the speed of the carriage upon 1ts bed plate. Since thewheel 18 is journaled on the frame 16, it is apparent that the framewill be constrained to move in unison with the wheel thus imparting tothe balls 14 the correct speed relatlve to the movement of the ways 11and 13. e

The platen carriage is moved by the usual form of spring drum or by anywell known and approved mechanism and is controlled by an escapeme'ntwheel 21 having apinion 22 which meshes with a rack, not shown butconnected with the movable carriage. Stops 23 and 24 are provided forlimiting the movement of the carriage on its bed, thus preventing theballs 14 from being carried beyond the ends of the ways 11 .and 13.

As will be seen from the drawings, the frame 16 may be stamped fromsheet metal with cross bars 25 having reinforcing ribs 26 formedthereon. The balls 14 are held in circular openings in upright flanges27 bent downwardly from the front and rear bars 28 and 29 respectivelyof the frame 16. It will be seen that the frame is, simple and of lightconstruction and that it fits between the parts of the platen carriagewithout inter fering with the working mechanism of the carriage andwithout requiring additional space.

I claim:

1. In a typewriter, a platen carriage support comprising a frame platehaving laterally projecting guideways at the opposite edges thereof, aplaten carriage comprising a plate arranged parallel with said frameplate and having laterally projecting guideways overlapping theguideways on said frame plate and forming ball races therewith, a ballretainer comprising a sheet metal frame interposed between said platessupported by said parallel plates, and a gear Wheel for engaging saidracks journaled on said sheet metal frame and arranged parallel with theroller engaging flanges thereof so that therollers in said ball raceswill be constrained to travel a distance equal to half the relativemovement between said parallel plates.

2. In a typewriter, a platen carnage frame comprising a horizontallydisposed plate having upstanding flanges at opposite edges thereof, saidflanges being bent into V-shape to form guideways at their sides, aplaten carriage comprising a plate arranged parallel with said frameplate and having downwardly extending flanges at the edges thereofoverlapping the flanges on said frame plate and cooperating therewith toform raeeways for roller bearings, a hearing retainer comprising a sheetmetal frame positioned between said parallel plates and adf'aeent theuppermost one thereof, said frame laving downwardly bent flangesextending between the parts of the raceways, roller bearings in saidraceways engaged by said downwardly bent flanges, racks secured to saidparallel plates, an ear extending down wardly from said sheet metalframe, and a pinionjournaled on said ear in a plane substantiallyparallel with said bearing engaging flanges, said pinion meshing withsaid racks for controlllng the movement of said bearing rollers.

In testimony whereof I have signed my name to this specification on this1st day of June A. D. 1920.

OTTO A. HOKANSON.

